The creatures had entered through another opening and had formed a circle around him, waiting to attack.

For half an hour, Carter battled furiously for his life in the lonely dungeon beneath the palace in the ancient city of Korvas.

The carcasses of the dead rats were piled high around him, but still they came and eventually they overpowered him by their very numbers.

John Carter went down by a terrific blow to his head from a snake-like tail.

He was half stunned, but he still clung tenaciously to his sword as he felt himself seized by the arms and dragged away into the darkness of an adjoining tunnel.

John Carter recovered fully when he was dragged through a pool of muddy water. He heard the rats greedily drinking, saw their green eyes gleaming in the darkness. The smell of freshly dug earth reached his nostrils and he realized that he was in a burrow far under the subterranean vaults of the palace.

Several rats on either side of him had hold of his arms by their forepaws as they dragged him along. It was very uncomfortable, and he wondered how much longer the journey would last.

Nor had he long to wait. The strange company finally came out into a huge underground cavern. Light from the outside filtered down through various openings in the ceiling above, its rays reflecting on thousands of gleaming stalactites of red sandstone. Massive stalagmites, huge sedimentary formations of grotesque shape, rose up from the floor of the cavern.

Among these formations on the floor were numerous dome-shaped mud huts.

As Carter was dragged by, he stared at a hut that several rats were constructing. The framework was composed of white sticks of various shapes plastered with mud from an underground stream bed. The white sticks were very irregular in length and size. One of the rats stopped work to gnaw at a stick. It looked like a bone.

As he was dragged closer, he saw that the stick was a human thigh bone!

The mud huts were studded with bones and skulls, upon some of which were still dangling hideously the vestiges of hair and skin. Carter noticed that the tops of all the skulls had been removed, neatly sliced off.

The earthman was dragged to a clearing in the center of the cavern. Here, upon a mound of skulls, sat a rat half again as large as the others.

The baleful, pink eyes of the creature glared at Carter as he was dragged up on top of the mound.

The beasts released their hold upon the earthman and descended to the bottom of the mound, leaving Carter alone with the large rat.

The long whiskers of the monster were constantly twitching as the thing sniffed at the man. It had lost one ear in some battle long ago and the other was bright with scar-tissue.

Its little pink eyes surveyed Carter for a long time while it fondly caressed its long, hairless tail with its one claw-like paw. This, evidently, was the King of the Rats.

"Lord of the Underworld," Carter thought, trying to hold his breath. The stench in the cavern was overwhelming.

Without taking his eyes from Carter's, the rat reached down and picked up a skull beside him and put it in front of Carter. This he repeated, picking up a skull from the other side and placing it beside the first. By repeating this, he eventually formed a little ring of topless heads in front of the earth-man.

Now, very judiciously, he climbed inside the circle of skulls and picking one of them up tossed it to Carter. The earthman caught it and tossed it back at the king.

This seemed to annoy his royal highness. He made no effort to catch the skull and it flew past him and went bouncing down the mound.

Instead, the king leaped up and down inside the little circle of skulls, at the same time emitting angry squeals. This was all very puzzling to the earthman. As he stood there, he became aware of two circles of rats forming at the base of the mound, each circle consisting of about a thousand animals. They began a weird dance, moving around the raised dais of bones counter-clockwise. The tail of each rat was gripped in the mouth of the following beast, thus forming a continuous chain.

There was no doubt that the earthman was in the center of a weird ritual. While he was ignorant of the exact nature of the ceremony, he had little doubt as to its final outcome. The countless barren skulls, the yellowed ones that filled the cavern were mute, horrible evidence of his final fate.

Where did the rats get all the bodies from which the skulls were obtained and why were the tops of those skulls missing? The City of Korvas, as every Martian schoolboy knew, had been deserted for a thousand years; yet many of the skulls and bones were recently picked clean of their flesh. Carter had seen no evidence in the city of any life other than the great white apes and the mysterious giant, and the rats themselves. However, there had been the woman's scream that he had heard earlier. This thought accentuated his ever-present anxiety over Dejah Thoris's safety and whereabouts.

This delay was tormenting. As the circles of rats closed in about him, the earthman's eyes eagerly searched for some avenue of escape.

The rats circled slowly, watching their king, who rose to his hind legs stamping his feet, thumping his tail. The mound of skulls echoed hollowly.

Faster danced the king and faster moved the circles of rats drawing ever closer to the mound.

The closer rats shot hungry glances at the earthman. Carter smiled grimly and gripped his sword more tightly. Strange that they should let him retain it.

More than one of the beasts would die before he was overcome, and the king would be the first to go. There was no doubt that he was to be sacrificed to furnish a gastronomic orgy.

Suddenly the king stopped his wild gyrations directly in front of Carter. The dancers halted instantly, watching, waiting.

A strange, growling squeal started deep in the king's throat and grew in volume to an ear-piercing shriek. The King of Rats stepped over the ring of skulls and advanced slowly toward Carter.

Once again the earthman glanced about seeking some means of escape from the mound. This time he looked up. The ceiling was at least fifty feet away. No native-born Martian would ever consider escaping in that direction.

But John Carter had been born on the planet Earth, and he had brought with him to Mars all the strength and agility of a trained athlete.

It was upon this, combined with the lesser gravity of Mars, that the earthman made his quick plan for the next moment. Tensely he waited for his opportunity. The ceremony was nearly concluded. The king was baring his fangs not a foot from Carter's neck.

The earthman's hand tightened on his sword-hilt; then the blade streaked from its scabbard. There was a blur of motion and a sickening smack. The king's head flew into the air and then rolled away, bouncing down the mound.

The other beasts beneath were stunned into silence, but only momentarily. Now, squealing wildly, they swarmed up the mount intent on tearing the earthman to pieces.

John Carter crouched and with a mighty leap his earthly muscles sent him shooting fifty feet up into the air.

Desperately he clutched and held to a hanging stalactite. Soon he was swinging on the hanging moss to the vast upper reaches of the cavern.

Once he looked down to see the rats milling and squealing in confusion beneath. One other fact he noted, also. Apparently there was only one means of entrance or exit into the dungeon that formed the rats' underground city, the same tunnel through which he had first been dragged.

Now, however, the earthman was intent upon finding some means of exit in the ceiling above.

At last he found a narrow opening; and plunging through a heavy curtain of moss Carter swung into a cave. There were several tunnels branching off into the darkness, most of them thickly hung with the sticky webs of the great Martian spider. They were evidently parts of a vast underground network of tunnels that had been fashioned long ages ago by the ancients who once inhabited Korvas.